Water-pressure underreamer



May 29, 1928.

1,671,47 F. w. JONES l WATER PRESSURE UNDERREAMER Original Filed Nov.7,. 1925 MMU Patented Mey 29, 192s.

UNITED STATES.

PATENT OFFICE.V4

wArna-rREssURE UNDERREAMER.

Application med November 7, 1923,seria1No. 673,282. Renewed February 29,192s.i

This .invention relates to well cutting or boring tools and is moreparticularly directed to underreamers utilized for enlarging the bore ofthe well to permit the lowering of aA Well casing.

An object of this invention is to provide a form of well cutting orboring device with cutters, the relative positions of which can bepositively controlled at will from the l1H top of the well so that thecutters may be advanced or retract from the cutting or reaming positionat any time and without necessarily changing the vertical position ofthe underreamer in the well.

Another object of this invention is to provide a. cutting device forWells provided with cutters actuated by means which will yield when thecutter encounters an overload or commences to ream more rapidly in thehole than the safety of the cutting or reaming device permits so thatrthe cutters of .the device may automaticallyl retract from the cuttingposition on the over-load to preserve the cutter and reaming device.Another important object of this invention is to provide a cuttingdevice or an underreamer with hydraulic means for advancing orretracting the cutter of the device to or from the reaining position,which hydraulic means may be controlled and operated from the top yofthe well without requiring any vertical motion'of the rea-ming device toeii'ect the operations of the cutters.

Various other objects and advantages of this invention will be apparentfrom the following description of a preferred eX- ample embodying theinvention and will present themselves through use or the practice of theinvention. l

In the drawings, Figure 1 is an elevation of the preferred embodiment ofthe invern tion.

Fig. 2 is a vertical longitudinal section of the underreaming deviceshown in Figure 1 taken at right angles to Figure 1 and illustratin thereaming device in position in a well ole with the cutters translated to4the reaming position.

Fig. 3 is a section similar to Figure 2 with the cutters illustratedinthe non-reamingposition and with the lower section of the reamingdevice-broken away.

Fig. 4 is a vertical longitudinal section at right angles to Figure 3.

tobe translated in a vertical direction rela-- Fig. 5 is a transversesection with the cutters in thel reaming position.

In the drawings, 2 designates the `body portion of the device whichcarries the operating elements of the tool, said body is preferablyprovided with a tool, joint 3 at the top by which the device may beattached to a stand of drill with a similar tool joint 5 in its lowerend to which other sections of the pipe or tools, such as indicated at6, may be attached.

pipe indicated by 4 and.

The @body 2 is provided with a vertical bore ating elementsv` of theroaming device or tool.

11 indicates a hydraulic'piston mounted the bore 7 of the body and thusadapted tive tothe body 2. .Preferably said piston is provided with oneor more packing rings 12 between the piston and Walls of the body 2. Thelower sectioof the 'piston 7 engages a seat 13 which is vieldingly urgedupward in the reaming device by a coil spring 14 seated in the springreceiving chamber` 9.

15 indicates two opposed cutters mounted by the body which cutters areadapted to be translated to and from a reaming or cut'-y ting position.Said cutters are preferably of plate shape or form and disposed to movein a horizontal plane'. The cutters are preferably of a lengthsubstantially equal to the width of the body 2 and are supported intransverse ways 16 in the body so that the same may be translated in adirection radial with respect to the body to expose their cutting edges.The piston 1.1 of the device is provided with a flat walled opening 17in its lower end through which the cutters 15 pass, said opening 17being 'of a width substantially equal to the cornbined width of thecutters 15 so that the cutters engage the flat walls and are iirmly heldagainst tilting in the device.

To provide means for actuating said critters to and "from the reamingposition by the motion of the piston 11, said piston y is preferablyprovided with members in each cutter extending in y sition,

form of pins 18 extending through the lower section of the piston andtransversely to the plates 15.'l said members or pins 18 extendthrough'and engage the walls of angled camways 19 in the cutters 15, thecam-ways in th'e'same parallel direction, but angled in a directionopposed to the ,cam-Ways in lthe opposed cutter `15.

The cutting edges of the cutters 15 are each Figure 3, where thecuttingedges of the vcutters 15'are held from lprotruding from the walls of thebody 2 of the device and the Same may be readily lowered through acastothe position where it is desired to infr rem. Fluid is then pumped downthe stand of pipe aga-inst the top of the piston.

11 which under suflicient pressure is forced downward against the coilspring 14, forcing the-pin 18 against the Walls of the angled cam-ways19 in the cutters 15, thereby causing the cutting edges of the cuttersto be translated radially beyond the outer walls of the body and intothe cutting positions as shown in Figure E2, where at the cutting edgesof the opposed cutters are on opposed sides of the body 2 of theunderreamer. The' underreamer is then rotated to cut or ream the holewhile the water pressure 1s maintained on the pistony 11. It 1s notnecessary to vertically translate the body of the under-` reamer totranslate the cutter 15 of the reaming device to and from the reamingpobut the position of the cutters may be controlled atvwill from theVtop of the well by proper application of the fluid or hydraulicpressure on the underreamer.

It is to be seen also that I have provided a form of cutting devicewherein the cutters 31st da of October, 1923.

may be yieldingly maintained in the reaming position by properapplication of the hydraulic pressure on the piston 11, but such cuttersare .not necessarily positively locked in such reaming position duringthe reaming or cutting operation but may yield under an excess load orinthrust to retract the cutting `edge from -the formation and thus underf such excess load the cutting edge of the rea'mer will not be destroyedand the life of the cutter laccordingly increased.

While I have described one form in which I this invention may beembodied, various modifications may be made in the form and details ofconstruction of the device Without vdeparting from the spirit of theinvention. This invention is of the scope set forth in the accompanyingclaims.

I claim: 1. VA rotary underreamer comprising a body, a rigid cuttermounted by the body, means for translating the cutter to change theposition of its cutting edge relative to the axis of the body, and adbris by-pass cut in said cutter back of its cutting edge. 2. In arotary underreamer, the lcombination of a body, a hydraulic operatedpiston mounted to reciprocate vertically in said body, a springlnormally urging the piston to upward posltion, vertical slots in thepiston and body, opposed plate forming cutters positioned in said slots,the cutters being radially movable to and from a reaming position, pinscarried by the piston and engaging angled cam-ways in the cuttersoperative to actuate the cutters throughreciprocation of the hydraulicpiston. 1

3.`In a rotary underreamer the combination of a body, ahydraulicoperated piston mounted to reciprocate vertically in said body', aspring below the piston normally urgingI the plston to anupwardposition, registering vertical slots in the pisto and body, opposedplate-form cutters positioned in said slots, the cutters being radiallymovable to and from a reaming position and restrained against verticalmovement by `engagementy with the ends of the vertical slots in thebody, pins carried by the piston and engaging angled camwa'ys in thecutters thereby operative to actuate the cutters upon reciprocation ofthe hydraulic piston.`

YSigned at Los Angeles, California, this.

F EDERICK WILLIAM JoNEs.

